542
O. Lavrynenko et al.
chemical composition of the solutions. The phase formation process was performed
in thermostat TS-1/80-SPU and it lasted up to 24 h at T 20 and 50 °C, afterward the
disk electrode was dried in the air atmosphere.
To analyze nanosized powders, we applied X-ray diffraction (XRD) method,
thermal analytical measurements (TG/DTG, DTA), X-ray fluorescence spectroscopy
(XRFS), Fourier transform infrared spectroscopy (FTIR), chemical–analytical investigations, magnetometry, transmission (TEM), and scanning electron microscopy
(SEM).
Computer-aided X-ray diffractometer (DRON–UM1) equipped with two Soller’s
slits and filtered radiation of cobalt anode CoK α was used to determine the phase
composition of the high disperse samples. The rate of the recording was set 1° · min
−1 ,
and the interfacial Wulff–Bragg’s angle made up 80°. Lattice parameters and
particle sizes were calculated according to obtained XRD-date. Thermogravimetric
and differential thermal analyses (TG-DTA) of the powders was performed in the
static air atmosphere by derivatograph Q-1500D (Hungary). The record was made
using computer data registration. The parameters of the pattern recording were the
following: the samples of 150 mg were heated at the rate 10 °C · min
−1 from 20 to
1000 °C; the sensitivity was 20 mg; TG—500, DTG—500, and DTA—250. The
samples were placed into a corundum crucible and covered by a quartz beaker
to create an equal temperature field. FTIR spectra were recorded for the mineral
phases placed on the “mirror”. Thermo Nicolet FTIR spectrometer in the range
4000–400 cm
−1 with 50 scans collected was used for measurement. A scanning
electron microscopy (SEM) using the JOEL-6700 microscope was applied to estimate the morphology of the surface structures. The weight ratio of iron to gold
or silver in the as-prepared samples was evaluated using an XRFS carried out in
the automatic spectrometer «ElvaX» equipped with a titanium anode. The magnetic
properties of the powders were studied using magnetometry performed with the help
of a magnetometer equipped by Hall sensor.
3 Results
3.1 The Nanoparticles Phase Composition Formed
on the Steel Surface in the Presence of Au(III) and Ag(I)
The phase composition of argentum-bearing samples formed on the St3 surface was
studied in the wide range of the AgNO 3 concentration when c(Ag
+ ) was varied from
0.5 to 25 mg/dm
3 . According to obtain data (Fig. 1a, b), two phases are formed in
the composition of the surface structures simultaneously—spinel ferrite (magnetite)
Fe3O4 (JCPDS file No 19-0629) and lepidocrocite (JCPDS file No 08-0098). The
O. Lavrynenko et al.
chemical composition of the solutions. The phase formation process was performed
in thermostat TS-1/80-SPU and it lasted up to 24 h at T 20 and 50 °C, afterward the
disk electrode was dried in the air atmosphere.
To analyze nanosized powders, we applied X-ray diffraction (XRD) method,
thermal analytical measurements (TG/DTG, DTA), X-ray fluorescence spectroscopy
(XRFS), Fourier transform infrared spectroscopy (FTIR), chemical–analytical investigations, magnetometry, transmission (TEM), and scanning electron microscopy
(SEM).
Computer-aided X-ray diffractometer (DRON–UM1) equipped with two Soller’s
slits and filtered radiation of cobalt anode CoK α was used to determine the phase
composition of the high disperse samples. The rate of the recording was set 1° · min
−1 ,
and the interfacial Wulff–Bragg’s angle made up 80°. Lattice parameters and
particle sizes were calculated according to obtained XRD-date. Thermogravimetric
and differential thermal analyses (TG-DTA) of the powders was performed in the
static air atmosphere by derivatograph Q-1500D (Hungary). The record was made
using computer data registration. The parameters of the pattern recording were the
following: the samples of 150 mg were heated at the rate 10 °C · min
−1 from 20 to
1000 °C; the sensitivity was 20 mg; TG—500, DTG—500, and DTA—250. The
samples were placed into a corundum crucible and covered by a quartz beaker
to create an equal temperature field. FTIR spectra were recorded for the mineral
phases placed on the “mirror”. Thermo Nicolet FTIR spectrometer in the range
4000–400 cm
−1 with 50 scans collected was used for measurement. A scanning
electron microscopy (SEM) using the JOEL-6700 microscope was applied to estimate the morphology of the surface structures. The weight ratio of iron to gold
or silver in the as-prepared samples was evaluated using an XRFS carried out in
the automatic spectrometer «ElvaX» equipped with a titanium anode. The magnetic
properties of the powders were studied using magnetometry performed with the help
of a magnetometer equipped by Hall sensor.
3 Results
3.1 The Nanoparticles Phase Composition Formed
on the Steel Surface in the Presence of Au(III) and Ag(I)
The phase composition of argentum-bearing samples formed on the St3 surface was
studied in the wide range of the AgNO 3 concentration when c(Ag
+ ) was varied from
0.5 to 25 mg/dm
3 . According to obtain data (Fig. 1a, b), two phases are formed in
the composition of the surface structures simultaneously—spinel ferrite (magnetite)
Fe3O4 (JCPDS file No 19-0629) and lepidocrocite (JCPDS file No 08-0098). The